Glycine

Glycine is the basic unit of protein and is one of the 21 amino acids that make up human protein. Except for the amino acid, the other amino acids are alpha amino acids. The amino acids constituting the protein molecule are all L-amino acids, but in recent years it has been confirmed that they can be isomeric as D-amino acids, and the specific mechanism has not been studied. Basic Information Specialist classification: growth and development check classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: No clinical significance. Normal value: Glycine (fluorescence assay): 163.9-237.1 μmol/L Above normal: Glycineemia. negative: Positive: Tips: When taking blood, it is necessary to avoid the effects of digestion and absorption of food. It should be taken in the early morning on an empty stomach. Normal value Fluorescence assay (200.5 ± 36.6) μmol / L. Clinical significance Abnormal result Increase: seen in glycineemia. Glycineemia is characterized by a significant increase in glycine concentration in blood, urine, and cerebrospinal fluid. It is divided into ketosis and non-ketotic types. The ketosis type is divided into propionateemia and methyldiacidemia. The disease is autosomal recessive, a disease with poor prognosis. The main symptoms of non-ketotic hyperglycemia are mental retardation and convulsions. The increase of glycine in blood and urine is not accompanied by ketosis. When organic acids in blood are decomposed, malonic acid and methylmalonic acid do not increase. The ketosis-type hyperglycineemia is characterized by the periodic occurrence of ketosis, and occurs in the neonatal period shortly after birth. At the same time as ketosis acidosis progresses, symptoms such as vomiting, lethargy, muscle relaxation, and dyspnea of ​​the respiratory tract occur, and most of them die during the baby. In the case of breast-free period, there may be mental and physical retardation, mainly due to abnormal metabolism of organic acids and elevated glycine in the blood. Propionic acidemia is characterized by acidosis, marked hypotonia, and decreased tendon reflex in the neonatal period. The propionic acid in the blood is significantly elevated. Methylmalonic acidemia has a significant increase in blood and urinary methylmalonic acid. The clinical symptoms are acidosis, vomiting, developmental disorders, and disturbance of consciousness from the neonatal period shortly after birth. In order to induce repetitive acidosis, glycine in the blood rises. It is believed that this disease may be caused by the disorder of methylmalonyl-CoA mutase (deoxyadenosylcobalamin coenzyme) during the process of controlling the conversion of methylmalonate-CoA to succinate-CoA. The enzyme uses active vitamin B12 as a coenzyme. The disease is divided into two types: vitamin B12-dependent and vitamin B12 non-reactive. The former gives a large amount of vitamin B12, and the excretion of methylmalonic acid is seen, and when the patient's cells are cultured in a medium supplemented with a large amount of vitamin B12, the conversion of methylmalonic acid to succinic acid becomes normal. It can be speculated that the process of converting vitamin B12 into deoxyadenosylcobalamin may be a hindrance. The latter does not respond even to a large amount of vitamin B12, which may be caused by a defect in methylmalonyl-CoA mutase. Need to check the crowd Newborns need to undergo this test. High results may be diseases: precautions for congenital hyperammonemia in children Preparation before inspection: The plasma amino acid concentration of normal people fluctuated day and night, with a peak at 8 to 10 in the morning and a trough at midnight. When taking blood, it is necessary to avoid the effects of digestion and absorption of food. It is better to take blood on an empty stomach in the morning. Requirements for inspection: 1. Patients with edema symptoms need to inform the doctor when checking. 2. In case of discomfort during cerebrospinal fluid extraction, the doctor should be informed immediately. Not suitable for people: Intracranial pressure is significantly increased or associated with significant papilledema is not appropriate. Inspection process On an empty stomach, the cerebrospinal fluid and blood are taken, and the doctor separates the components, examines them by fluorimetry, and then calculates the results. Not suitable for the crowd Intracranial pressure is significantly increased or associated with significant papilledema is not appropriate. Adverse reactions and risks Generally no complications and harm.

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